Just installed kdenlive on Ubuntu 8.10 for some videocutting, but was not functional. This is the same thing since at least 8.04. The error may look like this:
KCrash: Application 'kdenlive' crashing...
kdenlive: Fatal IO error: client killed
Could not find 'drkonqi' executable.
Dr. Konqi is a crash window for kde application, so this is not the reason. Just install these libraries and it should work:
sudo apt-get install libxcb-composite0 libxcb1-dbg libxcb1-dev